Role incongruity theory of prejudice (Eagly, 2004; Eagly & Diekman, in press; Eagly & Karau, 2002) states that prejudice arises from an incongruity between group stereotypes and social role characteristics (i.e., the behaviors prescribed by the social role), such that prejudice occurs when members of a group enter or attempt to enter into social roles that are stereotypically mismatched for their group. The specific aims of this application are to (a) expand role incongruity theory to other social categories such as race and the mentally ill and (b) test whether the degree of role incongruity predicts the amount of prejudice directed toward members of stigmatized groups better than overall attitudes toward the group. Toward this end, these studies attempt to both measure and manipulate participants' role congruency. In addition, these studies also assess the level of stress associated with the degree of role incongruency. The outcome of these studies will help researchers to understand prejudice more fully and thus can be used to reduce prejudice and discrimination, which will relieve the stress of members of stigmatized groups (e.g., African Americans, the mentally ill, women) experience because they are the targets of prejudice and improve their mental health.